The present invention generally relates to product dispensing systems and more specifically, but not exclusively, concerns product dispensing systems, which provide closed loop transfer of chemical concentrates from a source container to downstream mixing/blending devices.
Within the janitorial and sanitation industries, chemicals used to support various cleaning activities have tended to migrate toward becoming more concentrated. This reduces shipping costs since the water required for proper dilution is no longer being shipped as part of the product. On-hand inventory is reduced since the concentrated chemicals, when properly diluted, can produce many gallons of appropriate strength cleaning solutions. Concentrated chemicals can also be diluted at different rates on site to satisfy unique cleaning requirements, an option made much more difficult with pre-mixed solutions.
The dilution of chemical concentrates used for cleaning is typically accomplished with water. A class of devices commonly referred to as proportioners handles controlled mixing. These proportioners are usually connected to a water source and feature a mechanism for controlling the flow of water. When the water flow has been initiated, the chemical concentrate is introduced into the water stream at a predetermined rate by the proportioner. The blended liquid is then directed into another container such as a sink, bucket, or bottle.
Typically, to transport the concentrates to the proportioner, a small flexible tube runs from a fitting on the proportioner to the concentrate container. These containers, commonly one-gallon in size although other sizes are used, are placed on the floor, on a shelf or rack, or in a cabinet in close proximity to the proportioner. In many cases the top of the container is simply discarded and the tube placed into the open neck finish. The end of the tube can feature a small weight to prevent the tubing from floating on the liquid's surface.
These open concentrate bottles will likely be found in a variety of environments that have the potential of exposing the container to abuse such as tipping, falling, and impact. Any of these events have the potential of spilling or splashing the concentrate with subsequent physical damage to the surroundings, creation of hazardous material (HAZMAT) situations, and placing personnel at risk.
A number of attempts have been made to address the open container issue from caps with close fitting holes through which the tubing passes to devices that feature internal valving. These solutions, while successful to a point, still leave room for improvement. For example, in one type of dispensing system design, the opening of a bottle is closed by a throat plug that has a valve, which is normally closed. However, when a cap is mounted on the container, the valve automatically opens so as to permit fluid flow from the container. The valve in the throat plug contains a spring, which is compressed when the cap is installed. As the spring compresses, the valve opens. When the cap is removed, the spring expands so as to again close the valve. The repeated compression and decompression of the spring over time causes the spring to lose its resiliency. This loss of resiliency in the spring can create conditions in which the valve does not completely close such that leakage from the container can occur. In addition, these type of valve designs can create variable valve opening sizes, which in turn can restrict the flow rate and/or make the flow rate inconsistent. Moreover, the plug can be easily removed, thereby creating safety concerns. Typically, the spring is metallic, and the rest of the valve is plastic. With the metallic spring, recycling difficulties can be created.
These types of dispensing systems also require a high tolerance finish on the neck of the bottle so that no leakage occurs from the cap or plug. This high tolerance neck finish can make manufacturing of containers, such as blow molded containers, difficult. If the tolerance is not met, leakage from the container can result. Since the chemicals in the containers are typically stored in an undiluted or highly concentrated state, the chemicals tend to be very hazardous. It is therefore desirable that the closure for the containers be very difficult to remove once installed so as to avoid exposure to potentially hazardous chemicals. Given that the high tolerance neck finishes on containers, like blow molded plastic bottles, is technically difficult and/or economically impractical, most of the responsibility for sealing the container and preventing reopening of the container falls on the closure for the container. However, due to geometries involved with traditional closures, it is difficult to manufacture a closure with structures that prevent removal of the cap or closure from the container. For instance, with traditional plastic molding, anti-removal structures formed on the closure tend to make removal or stripping of the closure from the molds difficult, if not practically impossible. Due to their very nature, the anti-removal structures tend to hamper unscrewing of the closure from molds during ejection.
Thus, needs remain for further contributions in this area of technology.